1. Field of the Invention
This invention relates to a cell sampler to be used for sampling cells from the endometrium as a specimen to be used in cytodiagnosis for uterine cancer, particularly in cytodiagnosis for carcinoma corporis.
2. Description of the Prior Art
Recently the rate of uterine cancer infection has been on a gradual increase. As well known in the art, the sooner therapy is given, the higher becomes the possibility of complete healing from uterine cancer. Therefore, it is desirable to find a uterine cancer in an early stage by periodical medical examinations.
The uterine cancers are largely classified into carcinoma colli and carcinoma corporis, which occur to different sites and different cells. Accordingly, in order to make an accurate diagnosis, it is necessary to sample only the required cells exactly from an aimed site.
Above all, in case of carcinoma corporis which initially occurs to the epithelial cells (cylindrical epithelial cells) of the nucous membrane on the surface of the endometrium, sampling of the cylindrical epithelial cells is essential for early therapy. Generally, the uterine cavity has a pear-like shape with a breadth inwardly increasing from the narrow cervix to present a flat oval shape in section, so that it is extremely difficult to sample the intended cells precisely from the endometrium without meticulous skill and experience. Besides, in consideration of the risk that the carcinoma corporis has possibilities of occurring in any part of the endometrium, the sample cells have to be taken uniformly from the entire regions of the endometrium although it is often found difficult because of the complicated shape of the uterine cavity.
In this connection, there have been introduced samplers of various types which are designed to take sample cells from the endometrium.
For instance, Japanese Laid-Open Utility Model Application 58-80208 discloses a sampler which is composed of a rod member having a cell sampling portion at the fore end thereof and slidably inserted in a flexible tube. After inserting the flexible tube into the uterine cervix, the rod is slide back and forth a number of times, scraping the endometrium with the cell sampling portion at the fore end of the rod to pick up sample cells thereon.
However, this sort of sampler employing a cell sampling portion of a simple rod-like shape is almost incapable of sampling cells uniformly from the entire endometrium in the uterine cavity which has a complicated shape as mentioned hereinbefore. Especially, difficulties are encountered in sampling cells from the endometrium in the fundus regions of the uterine cavity.
Japanese Laid-Open Patent Application 58-16891 discloses a sampler employing a handle member which has, at its fore end, a resilient helical portion which is formed by twisting a flat strip about the axis thereof. After insertion into the uterine cavity, the helical portion is turned to sample cells from uterine cavity walls. Similarly to the sampler of the above-mentioned Japanese Laid-Open Utility Model Application 58-80208, the helical sampling end portion which has a rod-like shape is incapable of sampling cells uniformly from all regions of the endometrium or from the fundus regions of the uterine cavity. In addition, sampled cells are apt to be squeezed into the grooves of the helical end portion together with unnecessary cells (i.e., cells other than cylindrical epithelial cells) which might lead to an inaccurate diagnosis.